package com.hxkcloud.nurse.utils;

import android.view.View;
import android.view.ViewGroup;
import android.widget.GridView;
import android.widget.ListAdapter;
import android.widget.ListView;

import java.lang.reflect.Field;

/**
 * @author cys 在ScrollView中放入listView，使用如下函数可避免listview显示不全问题,在设置适配器之后调用这个函数
 */
public class ResetListViewCount {
	public static void setListViewHeightBasedOnChildren(ListView listView) {
		// 获取ListView对应的Adapter
		ListAdapter listAdapter = listView.getAdapter();
		if (listAdapter == null) {
			// pre-condition
			return;
		}

		int totalHeight = 0;
		for (int i = 0, len = listAdapter.getCount(); i < len; i++) { // listAdapter.getCount()返回数据项的数目
			View listItem = listAdapter.getView(i, null, listView);
			listItem.measure(0, 0); // 计算子项View 的宽高
			totalHeight += listItem.getMeasuredHeight(); // 统计所有子项的总高度
		}

		ViewGroup.LayoutParams params = listView.getLayoutParams();
		params.height = totalHeight
				+ (listView.getDividerHeight() * (listAdapter.getCount() - 1));
		// listView.getDividerHeight()获取子项间分隔符占用的高度
		// params.height最后得到整个ListView完整显示需要的高度
		listView.setLayoutParams(params);
	}
	public static void setGridViewHeightBasedOnChildren(GridView gridView) {
        // 获取GridView对应的Adapter
        ListAdapter listAdapter = gridView.getAdapter();
        if (listAdapter == null) {
                return;
        }
        int rows;
        int columns=0;
        int horizontalBorderHeight=0;
        Class<?> clazz=gridView.getClass();
        try {
                //利用反射，取得每行显示的个数
                Field column=clazz.getDeclaredField("mRequestedNumColumns");
                column.setAccessible(true);
                columns=(Integer)column.get(gridView);
                //利用反射，取得横向分割线高度
                Field horizontalSpacing=clazz.getDeclaredField("mRequestedHorizontalSpacing");
                horizontalSpacing.setAccessible(true);
                horizontalBorderHeight=(Integer)horizontalSpacing.get(gridView);
        } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
        }
        //判断数据总数除以每行个数是否整除。不能整除代表有多余，需要加一行
        if(listAdapter.getCount()%columns>0){
                rows=listAdapter.getCount()/columns+1;
        }else {
                rows=listAdapter.getCount()/columns;
        }
        int totalHeight = 0;
        for (int i = 0; i < rows; i++) { //只计算每项高度*行数
                View listItem = listAdapter.getView(i, null, gridView);
                listItem.measure(0, 0); // 计算子项View 的宽高
                totalHeight += listItem.getMeasuredHeight(); // 统计所有子项的总高度
        }
        ViewGroup.LayoutParams params = gridView.getLayoutParams();
        params.height = totalHeight+horizontalBorderHeight*(rows-1);//最后加上分割线总高度
        gridView.setLayoutParams(params);
}
}
